The present invention relates to a method for amounting a heavy equipment on a floating ship's hull. It also relates to an equipment prepared for the implementation of the method.
In the oil industry, it is known to moor, above an oilfield, a ship for the collecting, processing, temporary storage and off-loading of hydrocarbons. The hull of the ship is used for the storage of the hydrocarbons. The ship comprises on its deck an installation for processing the collected crude oil before the processed hydrocarbons are sent into the tanks provided in the hull of the ship. Such a ship is commonly referred to by the acronym “FPSO”, standing for the English expression “Floating Production, Storage and Off-loading”.
For the manufacture of such a ship, it is frequent that the hull and the tanks that are contained in it are manufactured on a first construction site and that the installation intended to be installed on top of the hull is manufactured on a second construction site remote from the first site.
Hulls of this type of ship have very large dimensions. Their length varies approximately from 200 to 400, their width from 35 to 70 m, with the total height of the hull varying from 30 to 45 m.
The installations that have to be mounted on the ship's hull typically have a total weight greater than 20,000 tonnes.
To enable their putting into position, and because of the lifting difficulties resulting from the very large dimensions of the hull, it is known to manufacture the production installation in the form of modules having a unit weight typically of the order to 1000 to 2500 tonnes. Each of the modules is pre-assembled on the ground and is then put into position on the ship with the help of handling means such as: land crane, floating crane, traveling-gantry crane, etc.
The installation that has to be mounted in the hull is thus broken down into modules that are pre-assembled on the ground. The modules are successively put into position on the ship's hull and then the fluid conveying connections, the electrical power and data transfer links are established between the different modules, on the one hand, and between the modules and the ship's hull on the other hand. Furthermore, the connections to the crude hydrocarbon pipes, on the one hand, and to the pipes for the dispatch of the preprocessed products, on the other hand, are established.
The time of assembly of the installation on the ship's hull is relatively long since a large number of modules must be placed successively on the deck and then these modules must be interconnected.